Machine for manufacturing heat sealing filter sheet materials



H. o. IRMSCHER 2,370,168

MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Feb. 27,1945.

Filed Feb. 24, 1941 9 Sheets-Sheet 1 INVENTOR. HANS O. HQMSCHEQ flTTOENEy Feb. 0. MSC

MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Filed Feb. 24, 1941 '9 Sheets-Sheet 2 a Q m r l' 88 a hie INVENTOR. HANS O. AQMSCHEE BY @Mibfi A' TTOQ/VE) 1945- H. o. IRMSCHER MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Filed Feb. 24, 1941' 9 Sheets-Sheet 3 Feb. 27, 1945. Q ,RMSCHER 2,370,168

MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS INVENTOR. HAWJ' 0. IRMJCHEE Feb. 27, 1945. H. o. IRMSCHER MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Filed Feb. 24, 1941 9 Sheets-Sheet 5 HANS 0. AQMSCHEE .47'7'OENE) Feb. 27, 1945. H. o. IRMSCHER MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Filed Feb. 24, 1941' 9 Sheets-Sheet 6 INVENTOR. HANS O, LQMSCHEP 5 ATTORNEY Feb. 27, 1945. H. o. IRMSCHER MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Filed Feb. 24, 1941 9 Sheets-Sheet 7 HANS 0. mMsc/me 14 77 01? N E y Feb. 27, 1945. Q lRMscHER 2,370,168

MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS,

Filed Feb. 24, 1941 9 Sheets-Sheet 8 fiX d ii? a c} u a m flit a Ema/1 Feb. 27, 1945. O l sc 2,370,168

MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Filed Feb. 24, 1941 9 Sheets-Sheet 9 Patented Feb. 27, 1945 MACHINE FOR MANUFACTURING HEAT SEALING FILTER SHEET MATERIALS Hans 0. Irmscher, Roslyn, N. Y., assignor to National Urn Bag 00., Inc., Long Island City, N. Y., a, corporation of New York Application February 24, 1941, Serial No. 380,230 In Canada Fcbruaryll, 1941 8 Claims.

The invention relates to the manufacture of a heat, sealing filter sheet material, and more particularly is directed to machines for applying on a pervious textile or paper base layer weg an adhering superficial coating comprising porous film r lamina which has heat scaling properties without appreciably decreasing the original porosity or practically effecting the filtering capacity of said web. Said heat sealing filter sheet materials may be like those described in application Ser. No. 370,688, filed December 18, 1940, by Theodore F. Menzel for use in making infusion packages or the like.

Among the objects of the invention is to gen erally improve machines of the character described which shall comprise few and simple parts that are readily assembled to form a rugged easily operated apparatus of high output capacity. which shall be inexpensive to construct, and which shall be practical and eflicient to a high degree in use.

Other object of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exemplified in the constructions hereinafter described and of which the scope of application will be indicated in the folio-wing claims.

In the accompanying drawings, in which are shown va'rious possible illustrative embodiments of this invention,

Figs. 1 and 2 are side elevational and top plan views, respectively, of a machine for manufacturing a heat sealing filter sheet material constructed to embody the invention;

Figs. 2a, 2b and 2c are detailed enlarged sectional views showing successive sectional views taken during the passage of a vegetable fibrous pulp porous base layer web through the machine to provide said heat sealing filter sheet material;

Fig. 3 is a cross-sectional view of the feeding end of the improved machine taken on line 33 in Fig. 2;

Fig. 4 is a detailed cross-sectional view taken on line 4-4 in Fig. 3;

Fig. 5 is a cross-sectional view of the discharge end of the improved machine taken on line 55 in Fig. 2;

Figs. 6 and 7 are detailed cross-sectional views taken on line 0-6 and 1-4, respectively, in Fig. 5;

Fig. 8 is a sectional view as 8-8 in Fig. 6;

Figs. 9 and 10 are cross-sectional views taken seen from line on lines 0-! and ill-l0, respectively, in Fig. 3;

Figs. 11 and 13 are front and rear side elevational views, respectively, of the feeding end of invention which, as seen from Figs. 1, 3, 5 and '9, ha a suitable elongated horizontally extending bed plate 2| formed with downwardly projecting edge flanges zla, said bed plate 2| being raised on spaced vertical supports or legs 22 to-a desired level over a fioor F; The feeding end 2lb of the bed plate 2|, as shown in Figs. 1, 2, 3 and 11, rigidly supports an outwardly extending bracket 23 which terminates at 23a in a firm anchorage for one end 24a of a stud shaft '24 on which a suitable proportioned reel or spool 25 is rotatably' mounted, as shown in Fig. 4. A screw set collar 26 on the free end 241) of said shaft 24 removably retains-the reel 25 against.

accidental displacement from said shaft 24.

The reel 25 has wound about a core 25a and between spaced disc sides 25b and 250 thereof a supply roll R of a relatively thin pervious base layer web 21 which is to be superficially coated I by machine 2 to form the heat sealing filter sheet material 28 in the manner hereinafter described. .The disc side 25b may be made remov able from 'the core 25a by using a split collar 29 releasably screw threaded and bolted in position, the disc side 250 being made integral with said core 25a and with an aligning boss 25d, as shown in detail in Fig. 4. The boss 25d has a peripheral groove 25c into which a releasably adjustable spring latch 25f engages. The latter is hinged at 250 for movement on the bracket terminal 23a, as shown in Figs. 13 and 14, and serves to adjust the reel 25 with the roll R along the shaft 24 so that the travel of the web 21 may be shifted for alignment with respect to any requirement of the subsequent passage of said web 21 through the machine 20. Said aligning adjustment is accomplished by means of a hand wheel 25h screwed on a threaded bolt 25:! con A compression spring the reel 25 may be readily shifted along the stud shaft 24 as required for adjustably aligning the travel of the web 27? in the operation of the machine 20.

As shown in Figs. 1, 3 and 11, supported to extend frontward from the bracket 23 on a stub shaft 23?) is a lever arm 44' carrying a brake shoe 45 having a suitable non-abrasive lining 45a, said arm 44 and shoe 45 being adjustably balanced by a slidable counterweight 46. The brake shoe 45 is so arranged as to smoothly press the lining 45a-thereof against the supply roll R to serve as a drag for preventing accidental unwinding, the counterweight 48 being adjusted for varying the pressure to permit a smooth and even feed of the travelling web 21 to the requirement of the operations of machine 20.

In order that the travelling webs 21 be brought to the proper height required when Passing horizontally through the machine 20, a levelling roller 41 mounted on upright fitting 41a is provided, the latter being supported from the upper side of bracket 23. Before said web 21 reaches the roller 41 it passes under a slack take-up roller 48 which is hinged at 48a by arms 48b from the upright fitting 41a. The take-up roller 48 compensates for any irregularities of the unwinding of the web 21 from the roll R on the reel 25.

'I'hebase layer web 2? may be a continuous paper strip made from a vegetable fibrous pulp stock, and when processed by machine 20 in the manner hereinafter described forms the heat sealing filter paper sheet 28. The pervious paper layer web 21 preferably is of a quality having a relatively high wet strength capable of withstanding immersion in boiling water without damage or disintegration, yet permitting ready passage therethrough of the water of immersion for forming a brew and straining the contents of a bag when used for making. bags for tea-balls; or the like infusion package (not shown).

Extending over the bed plate end 2422 is a coating spreader, denoted generally at S, which is seen from Fig. 3 to include an upright supply receptacle holding a dry powdery coating material 34 in bulk which is fed therefrom by a rotary fluted-facedroller 32 for uniformly spreading said coating material 3| on the underlying travelling web 21 in quantities measured by the contents of the roller flutes 32a and'in proportion to the rate of rotation of the roller 32.

The coating material 3| may be a finely divided plastic of a natural or synthetic thermoplastic resin, such for example of the phenol, urea, formaldehyde, glycerol, phthalic anhydride, acetylene, rubber or petroleum group. The thermoplastic resin used in the coating process here described in the operation of machine 26 is a. -thermosetting polymerizing resinous product,

such as a finely powdered copolymer of vinyl chloride and vinyl acetate. This latter will make the heat sealing filter sheet material 23 with a thermosetting superficial coating on the base layer web 21 after being processed by machine 20 with no part of said sheet material 23 that will dissolve, give ofl any odor, alter the taste, or

otherwise impart toxic oinjurious effects when used in connection with a food product such as in making brews with tea and coffee balls.

In order to assure an even feed and uniform spread of the coating material 3| onto the traveling web 21, a rotary brush 34 operates to sweep said material 3! from the roller flutes 32a over the web 27, a secondary rotary brush 33 spaced from brush 34 removes any material 3| from flutes 320 that the brush 34 fails to sweep out, and an auxiliary rotary brush cooperates to keep the brush 34 clean. The location of the fluted roller 32, brushes 33, 34 and 35 is shown in Fig. 3, the arrows indicating their relative operating rotation for the purposes above described.

As shown in Fig. 9, the receptacle "is supported by bolted front and rear extending pieces 30a to upstand on spaced side plates 36 between which the fluted roller 32 and brushes 33, 34 and 35 are journalled and between which the web 21 travels horizontally. The side plates 36 in turn may be bolted upright to overhang spaced upright supporting pieces 31 which are rigidly mounted on the bed plate 2| as shown in Figs. 3, 9, 11 and 13. A suitable collection pan 36 is removably suspended from lower edges of the side plates 36 for catching any surplus spillage of the coating material 3| dropping from the travelling web 21. The side plates 36 maybe formed with spaced aligned bearing block portions 32b for the shaft 32c which carry the fluted roller '32 and suitable spaced aligned bearing block portions which carry shafts 33a, 34a and 35a of the brushes 33, 34 and 35, respectively. The upright supporting pieces 3l may also be formed with spaced aligned bearings 31a for a cross shaft 38 having a rearwardly overhanging sprocket 39 for driving achain 43 of a suitable power transmission T hereinafter described in more detail.

As shown in Figs. 11 and 12, the front and rear ends 34b and 35b of the brush shafts 34a and 35a, respectively, may be mounted in suitable floating supports, as for example, by having said shaft ends 34b and 35b extending through 'elongated openings 34c and 350, respectively, said shaft ends 34b and 35b being journalled in spaced duplex arms 49a and 43b of a bell crank fitting 49 which is pivoted at shaft 430 on upwardly extending supports 4911. Another arm 49c of the bell crank 49 is resiliently supported on a compression spring 499 encircling a bolt 49] so that by adjusting the length of the bolt 49/ the bell crank fitting 49 is swung on the pivot 480 to move the shaft ends 34b and 36b with the brushes 34 and 35, whereby their effective sweeping action on the fluted'roller32 may be controlled.

As shown in Figs. 9, 11 and 13, on the front end 32d of the fluted roller shaft 320 there is mounted a cam oscillating wheel 32:: which coopcrates with a roller end 32! of a double ended lever 32g pivoted on a shaft 32h, the latter being secured on an upward extension 361) of the front side plate 36. The upper end 32k of the lever 329 is connected with a link 32-l through the shaft 3271. and a, crank shaft 32m, both shafts 32h. and 32m extending through the walls of the receptacle 33 to operate upwardly extending breaker plate 321i. and downwardly extending feed plate 32p, respectively, said plates being mounted operative position against cam oscillating wheel The travelling base layer 21 in passing through spreader 8 has the upper surface thereof covered with the powdered coating material I after which it passes through a heater and clamping unit of suitable construction. Said unit may comprise an electrical resistance heater, denoted generally at H, spaced from spreader 8 along bed plate 2! for heating the powdered coatins material ii to a degree sufllcient only to cause said coating material 3| to become plastic or molten, and flow, that is, to soften, coalesce and cohere as at Ila in Fig. 3, and a suitable pressure means denoted generally at P, spaced from the heater H along bed plate 2| as shown in Figs. 1, 2, 3, 11 and 13. The travelling web 21 with the coating material 3la in heated plastic state after passing through heater H is then immediately passed through the pressure means P. The coating material 3|a on the web 21 after leaving the pressure means P is then a pervious film, lamina or superficial coating adhering to the base layer upper surface.

The degree of heat applied to said coating material 3! by heater H should be insuillcient to cause a permanent thermosetting thereof but be referred to as being "thermosctic. a

with the partially fused" superficial coatings formed of copolymer of vinyl chloride and vinyl acetate, such thermosetting permanent sealing fusion of the seam will take place when heated. to' about 130C. and pressed by said suitable clamping means. L

. It has been found in practice that a 6 /2 pound fibrous pulp stock sheet of approximately .001 inch thick forms a practical filter paper layer web 21 for the purposes described herein. 0n said layer web 21 the finely powdered copolymer described and as illustrated in the drawings, the

should form on pressing and cooling the superi'ecting the filtering capacity of the paper base layer 21.

Should it be desired to have a machine embodying the invention of small output capacity, the web 21 with the adhering superficial coating may be slowly passed therethrough and as they leave the pressur means P can be cooled to about room temperature and coiled up on suitable rewinding means W in the manner hereinafter described and as shown in Figs. 1, 5 and 6. When so cooled the pressed superficial coating hardens and will hereinafter be referred to as being in a partially fused state or as being applied to the web, 21 by "partial fusion. In this state the pressed superficial coating is dry and forms with base layer 21 the heat sealing filter sheet material 28 which remains flexible and may be coiled up in rollsC by rewinding means 'W ready for use in the manufacture of bags of infusion packages or the like.

The heat sealing filter sheet material 28 when used for making containers or bags for tea-balls or the like has the superficial coating side thereof on the interior surface of such" bags. The edge joints or seams, and top and bottom closure seams, being made by having said coating portions thereof in face to face relation, are

machine 20 is constructed for quantity production. Consequently, the operation is carried out at a relatively higher travel speed of the base layer 21 than in providing the heater and clamping unit comprising but a single heater H and pressure means P, as so far described. Machine 20, therefore, depending on the capacity required, is constructed to include one ,/or more additional heater and clamping units, similar to heater H a and pressure means P, as for example, electrical resistance heaters Hi and H2 coacting with pressure means Pi and P2, respectively. Said units comprise heaters H and pressure means P, heater HI and pressure means PI and heater H2 and pressure means P2 arranged in spaced tandem, that is, series relation along the bed plate 2|, through which the travelling web 21 with the coating material successively passes until it is coiled up in the roll C by the rewinder W, as is shown in Figs. 1, 2 and 5. The final product turned out by machine 20 in every case will be heat sealing filter sheet 28 havin the construction and properties above described.

A more detailed description of the portions of machine 20 which have been denoted generally as H, HI, H2, P, Pl, P2, W and T, will now be given.

The heater H as seen from Figs, 1, 3, 10, 11

and 13 may comprise an electrical resistance type of heater plate M of any well known construction arranged when in effective position to extend parallel to and preferably in close proximity over the path of travel of the web 21. Said plate ll is supported on a bolted bar Ma extending between the upright hanger 31 and pillow blocks pressed together and thermoset at a final fusion 1 temperature by suitable clamping means (not shown) of any well understoodconstruction to unite the parts from such edge joints and closure seams sealed in permanently fused adhesion as described in said Menzel application. The above described thermosetting property of filter sheet material 28 at a final fusion temperature 50 of the pressure means P. Said, heater plate 4| is mounted for swinging movement, shown in full and dotted line positions in Fig. 10, on a hinged fitting lb so that free access to the underlying travelling web 21 with coating material 3| may be had when desired. Said heater plate ll construction may also include a releasable, quick-adjusting fastening means Me on the side thereof opposite to' the hinged portion lib, a back stop lid for limiting the swing movement thereof, and. a suitable lift handle Me adjacent said fastening means c. There may also be provided a guard or shield 4 if secured at a spaced distance from and extending to overlie the upper exposed surface of the heater plate 4| to protect the same from being damaged or causing damage or injury.

The pressure means P which cooperates with heater H. as seen from Figs. 1, 2, 3, 11, 15 and 16, may comprise a pair of rollers and 52, respectively, mounted on vertically aligned upper and lower shafts 5|a and 52a, respectively, the latter being Journalled betweenthe spaced pillow blocks 50 mounted on the bed plate 2|. Between said rollers 5| and 52th e web 21 carrying the molten coating material 5|a is compressed. The shafts 5|a and 52a are geared, as at 53, for rotation as shown by the arrows in Fig. 15, to correspond with the direction of travel of the web 21. Bearings 5| b, in which the ends of the upper shaft 5 In turn, may be movable or float mounted, preferably being resiliently supported by concentrically arranged compression springs 55 and 55a. The degree of resiliency may beadjusted by jack screws 55, one for each bearing 5|b as shown in Figs. and, i6. Locknuts 55a on jack screws 55 serve to retain any set adjustment of said resilient effect. Bearings 52b, in which the lower shaft 52 turns, may be formed as part of the pillow blocks 50.

To facilitate threading or removing the web 21 from between the rollers 5| and 52 a pair of spaced levers 55 having cam lift portions 55a is provided, one under each bearing 5|d, said levers 55 being pivoted as to 55b. Suitable handle ends 55c on each of said levers 55 are provided to raise the bearings 5|b with the ends of the shaft 5|a and roller 5| against the action of the springs 55 and 550.

Since the molten coating material when it is compressed between the rollers 5| and 52 is still in a plastic state, the surface of the upper roller 5| has been found to become smeared with said coating material when contacting therewith. To overcome this diificulty a suitable scraper or doctor 51 mounted adjacent the roller 5| is provided to press against saidsurface as at 5|c, the scrapings being collected in a suitably demountable upper receptacle 58, as shown in Fig. 15. Since the lower roller 52 is somewhat longer than the width of the web 21, aid roller 52 may also become smeared in use; To maintain the surface of said roller 52 clean, another scraper or doctor 59 is provided to press against said latter surface as at 52c,.the scrapings being collected in a suitably demountable lower receptacle 60, as shown in Fig. 15. a

Spring clips 51a and 55a may be provided for releasably retaining the receptacles 59 and 55, respectively, in their mounted positions. f

The heaters HI and H2, as seen from Figs. 1, 5 and 7, may each comprise electrical resistance type of heat plate 5| of similar construction as heat plat ll except; that heat plate 5| may be longer to give it greater effective heat radiating area and to span the distance between the successive pressure means P and PI andfrom Pl to P2 which preferably is made longer than the distance from the spreader S to the first pressure means P. Said heater plates iii are mounted on bolted bars 5|a and hinged by fitting 5") in the manner similar to heater plate 5| so that free access to the underlying travelling web with the coating material leaving pressure means P may be had when desired.

Said heater plates 5| also each include quick adjusting releasable fastening means 5|c, back stop 5|d, handle He and guards or shields 5|! like the similar parts of heater H above described. Because of the large span of heaters HI and H2 there may be in addition provided for each a centrally located roller 82 over which the web and coating material being processed passes and side ramps 53 extendingin opposite directions from underside of the web. Preferably the roller 52 and ramps 55 form astru'cture that raises the level of the web higher than the normal horizontal alignment of the passage of the web be-,

' tween the rollers of the'pressure means 1, PI

and P2, the ramps 55 each sloping down from the supporting roller 52 to each of the pressure means PI and P2. This construction aids in keeping the web taut during starting, stopping and running thereof. Each of the ramps 55 may be rigidly supported in position by suitable stanchion securedonthebedplatefl.

The pressure means PI and P2 as seen from Figs. 1 and 5, may each be constructed'like pressure means P described above and as shown in detailed section in Figs. 15 and 16. Pressure 5 means PI and P2, however, under normal conditions do not require doctors or scraper or receptacles for scrapings as does pressure mean P, otherwise th construction and operation are similar, there being provided for each pillow block 15 supported on bed plate 2| upper and lower rollers II and 12, respectively, mounted on shafts Ila and 120, respectively, which are geared as at 15, said shaft ends being journalled in floating bearings, resiliently controlled by spring pressed releasably locked lack screw 15. The only differenc between pressure means P, PI and P2 is that the sets of rollers 5| and 52- of pressure means P and II and 12 of pressure means PI and P2 are successively of slightly greater diameter, that is,

rollers 5| and 52 are smallest, and rollers H and I2 of pressure means P2 are a little larger than rollers II and. I2 ofpressure means Pl. This difference of diameter assures that the heated web in passing through the machine 25 is kept taut and in a slight tension condition found favorable for the production of heat sealing filter sheet material 25.

To aid in the reminding of the coated web 2:

after leaving the pressure means P2, a guiding roller 11 is mounted on bracket arm 15, the latter being supported from the pillow block 15, retaining said coated web 25 in the most desired take-of! location for the entire range of the coilingoperatlon of rollCona reel 55.

Referring now to Figs. 1, 2 and 5, the travelling web with the adhering superficial coatings forming the filter sheet material 25 as it through pressure means P2 and beyond is now in a finished state ready to be coiled up in roll C by suitable rewinding means W. The roll C preferably is coiled up on take-up reel or spool 55 shown in Figs. 5, 6 and 8. Like web supply reel 25, reel 55 may have a core 55a, a disc side 55c integrally formed with said core 55a, removable disc side 55?), bolted split collar 55 on end of core 55a for retaining the removable disc side 55b secured thereto, set screw collar 55 on end of ashaft 55 for retaining the reel 55 from displacementtherefrom, an end 55a of the stud shaft 55 being Journalledfor rotation on a terminal bearing 55a of an outwardly extending bracket 55 which is bolted on the end 2|c of the bed plate 2| oppositetheendflb.

The shaft 55 may project through the bearing 55a and carry thereon a pinned drive sprocket-52 which engages with a drive chain 52a. Said shaft 55 between the bearing 53a and reel 55 may also carry to turn therewith a brake drum 5| which cooperates with a suitable spring adjustable band take-up reel 85 will be uniformly stretched with- I out tearing. r

As the rewindingof the hot sheet material 28 passing to the rewinder W proceeds, it may be brought down to room temperature, if necessary, while it is being coiled up by providing suitable cooling means, as for example, an electric fan 88 adjustable to direct a flow of air against the roll C. The fan 88 may be bolted at 88a on one of the bed plate legs 22, and supplied with power from a suitable source (not shown) in the well understood manner.

In Figs. 2a, 2b and 2c are shown progressive secthe finished heat sealing filter sheet material 28.

which is re-rolled in coil C.

The power transmission T as shown in Fig. 1. may be supplied through an electric motor 80 with a speed changer 90a and speed reducing means 801), if desired, all installed on a platform 35 supported on legs 22 under the bed plate 2|. From the speed reducing means 90b the rotary brush 34 is driven through a first counter shaft 9| having mounted to turn therewith a belt driven pulley Ma and a drive pulley 9|b, the latter by a cross belt 9 ie which drives a pulley 34:: mounted to turn with the front extension of shaft 34d on which the rotary brush 34 is secured, as shown in Figs. 1 and 11. The shaft 3| is suspended from the bed plate 2| on spaced hanger bearings 92, the drive pulley 9") being mounted on a front overhanging extension 3|d of counter shaft 9| as shown in Fig. 9. The counter shaft 9| also ex tends through the bearings 92 rearwardly to carry abutted'overhanging pulleys 8|e and 9|). As shown in Figs. 9 and 13, the pulley 9|e through a belt Sig drives a pulley 330 secured to turn with the sweep brush shaft 33a and the pulley 9|) through belt 9th drives a pulley 93mounted to turn on a rearward extension 230 of the stud shaft 23?) which is supported to extendarearwardly from bracket 23. .Said shaft extension 230 also carries a drive pulley 93b which through a cross belt 830 drives a pulley 35a secured to turn with auxilliary brush shaft 351).

There is also provided a set of mesh gears, one gear 34c mounted on a rearward extension of the fluted roller shaft 320, the other gear 34e mounted for turning on a shaft 34! supported on the end of an adjustable carrier plate 349, the shaft 34f carrying a drive sprocket 34h which through the chain belt 40 is driven by said cross shaft 38. By means of a slot and bolt connection 34 the carrier plate 340 may be adjusted to permit changes in the relative size of meshed gears 34:: whereby the speeds of the fluted gear 32 can be varied as desired. The cross shaft 38 through a worm and wheel denoted generally at 4| is driven from a line shaft 42 extending practically the length of the machine 20 along the rear side thereof above the level of bed plate 2|. Said line shaft 42 is supported in suitable spaced hanger bearings 43, and at each of the pressure means P, PI and P2 there is provided worm gear drives 4|a which connect directly with the lower roller shafts Ila and Ho of said pressure means P and P| P2, respectively. The above described'transmlssion through line shaft 42 connects with the drive chain 821: operating the rewlnding means W by means of a sprocket wheel 4|b mounted on roller shaft 12a of the pressure means P2, as shown in Figs. 2, 5 and 6, the line shaft 42 being provided with a sprocket 42a I driven by chain We from the reduction gearing 90b as shown in Figs. 1, 15 and 1'7.

The operation of improved machine 28 for manufacturing heat sealing filter sheet material 28 will now be readily understood. After the parts of the machine have been constructed and assembled to operate as shown in the drawings and above described, a roll R of porous base layer web 21 is mounted in reel 25 to provide a continuous supply source of the travelling web. It has been found in practise that when said base layer is made of filter paper vegetable fibrous pulp, that a stock sheet of approximately .001 inch thick gives satisfactory results for the purposes described. The base layer web 21 is successively drawn under roller 48 over roller 41, through spreader S, that is, between side plates 36 and under the fluted roller 32 and brushes 33, 34 and 35, all as shown in Fig. 3. Then with the heater plate 4| of heater H swung in open position shown in dotted lines in Fig. 10 and the upper roller 5| of the pressure means P pried up from its operative position against lower roller 52 by depressing levers 58, said web 21 is passed therethrough. In a like manner, the leading end of web 21 is next passed over ramp reflector 63 and supporting roller 62 with'the heater plates SI of .the heaters HI and H2 swung open and between upper roller II and lower rollers '12 pried apart by levers 16 of pressure means PI and P2, as is clear from Figs. 1, 3 and 5. Finally, the

40 leading and of the web 21 is passed over and beyond roller TI to the take-up reel 85 for recoiling. With the web 21 stretched taut, the parts of heater H, HI and H2 swing into effective position as shown in full lines in Figs. 10 and 7, and the upper rollers BI and ll of pressure means P, H and P2 released to clamp the web. The machine 2|) is now ready to be started in operation by first connecting in circuit the heaters H, HI and H2 and then the motor 38 to suitable electric supply sources (not shown) in the well understood manner.

The running of the motor through part of power transmission T above described agitates the coating material 3| in receptacle 30 to freely flow and uniformly feed the rotation of fluted roller 32 for distribution over the upper surface of the web 21 travelling thereunder. The web 21 with said coating material 3| in passing through heater H is then pressed by pressure means P into surface of web 21 to provide a partially fused superficial coating thereon. The coated travelling web after leaving pressure means P is successively heated and pressed'as it passes through the heater H and pressure means PI, and again through heater H2 and pressure means P2 until the heat sealing filter sheet material 28 having the characteristics above described leaves the pressure means P2, said sheet material being wound up in coil C on the reel 85 of the rewinding means W. The speed of the travelling web through the machine 20 may be varied by the speed changer a in conventional manner where the motor 80 is of the constant speed type.

Should the travelling web 21 vary from a central alignment with respect to the 'rollers of pressure means P, PI and P2 and the reel 85 of the rewinding means W, the said alignment may be adjusted by the screwing handwheel 25b.

in or out on the bolt 257', as is obvious from Figs. I 5 4, 13 and 14.

Should it be desired to change the speeds of the fluted roller 32 for increasing or decreasing spraying the material 3| with respect to the travel movement of the web 21 through the mal0 chine 20, the set of gears 34c may be replaced by others and the slot and bolt connection 341 adjusted for remeshing the replaced gears in the well understood manner.

While machine 20 has been described above 15 as operating with a vegetable fibrous pulp porous paper base layer web 21, it is understood that other kinds of base layer web may be used for producing heat sealing filter sheet material 28, such' for example as filter sheet material formed of cotton staple pulp, thin sheets of perforated parchment paper and Cellophane, cotton gauze textile sheets or the like. These various kinds of base layer webs used in producing heat sealing filter sheet'material 28 are fully described in said Menzel application aforementioned.

In Fig. 17 is shown a modified form of machine I20 constructed to embody the invention. Machine I20 may be like machine 20 described above 30 and shown in Figs. 1 to 16, inclusive, except that the units of machine 20 comprising heater HI and pressure means PI and heater H2 are replaced by an enclosed heater system The latter may comprise a suitable heat source, as for example a gas burner G for heating air in an oven 0 which connects with the inlet end of a blower B. The hot air from the blower B circulates the air through a supply conduit L into the sheet material finishing end of closed heating chamber or dryer D through which the web 21 with the, molten and pressed material passes from the pressure means P. The hot air is exhausted at the sheet material feeding end and is returned to the oven inlet I for reheating and recirculation. To control the fiow of air through the system, suitable valves V may be provided. Spaced covered hand holes E along the dryer D serve to 'give ready access to the interior of the drier D for threading the web therethrough between pressure means P and P2. Machine I20 operates, in the same manner as machine 20 described above with the exception that the travelling web is partially fused with coating material in the closed dryer D which may be of suitable length. The travelling web is held taut by making the rollers of pressure means P2 of greater diameter than those of pressure means P running at the same speed.

It will thus be seen that the machine as provided achieves the objects of the invention and is well adapted to meet the conditions of practical use in an efficientmanner.

As various embodiments might bemade in the above invention and as various changes might be made in the embodiments above set forth, it is 5 to be understood that all matters herein set forth or shown in the accompanying drawings 7 are to be interpreted as illustrative and not in av limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. In a machine of the character described, a source for supplying a travelling porous layer base web, a receptacle for coating material including a distributing means mounted to uni- 76 formly deposit coating material from the receptacle ina uniform thin layer on to a. travelling web coming from said source, and means including a plurality of heaters and sets of roll ers alternatelyspaced apart along the path of movement of said web with said thin layer of coating material for partially fusing" and for compressing the same in position as deposited by the distributing means by successive action to form a pervious'superficial extremely thin lamina adhering to the web in the production of a along the path of movement of said web for uniformly feeding coating material from the receptacle on to the travelling web coming from said source, means including a heater spaced from said distributing means to extend over the coating material on said web for partially fusing" the coating material in same position as fed onto the web by the distributing means, and means for pressing the heated partially fused coating into a pervious superficial extremely thin lamina adhering to the web to provide therewith a thermosetic" heat sealing filter sheet material of substantially the same filtering capacity as the porous travelling web, said pressing means acting to advance said web at a uniform speed through the machine.

3. In the machine as defined in claim 1 which includes a power transmission means connecting with said rollers for advancing the web with coating continuously through the machine in a taut condition and means for locating the distributing and "partial fusing means to retain the travelling web with the coating material in a substantially horizontal plane during the passage therealong.

4. The machine defined in claim 2 which includes a power transmission means for moving the travelling web through the operation of said pressing means.

5. In a machine of the character described, a source for supplying a travelling porous base web. a receptacle for coating material-including a distributing means mounted along the path of travel of said webs for continuously depositing measured quantities of the coating material from the receptacle and depositing same in a layer of uniform thickness onto the travelling web, means including a plurality of spaced heater and pressure units, each of which acts in succession to partial fuse the coating material in the deposited position on the web until a pervious superficial lamina is formed adhering to the web providing therewith a thermosetic heat sealing filter sheet material.

6-. A machine of the character described coinprising a bed frame, a sourcefor supplying a travelling filter base web on one end of said frame, a coating material receptacle mounted on the frame spaced from said supply source, distributing means for uniformly depositing coating material from the receptacle on to the travelling web coming from said source, a heater spaced from the distributing means for partially fusing the coating material carried on said web in the same position as deposited by the distributing means, means carried on the frame adjacent said heater for pressing said partially fused coating material into a pervious superficial extremely thin lamina adhering to said web to provide therewith a thermosetic heat sealing filter sheet material of substantially the same filtering capacity as said travelling web, said pressing means acting to continuously advance the web for the coating distributing and "partially fusing" thereof through the machine in taut condition including a set of rollers between which the web with the partially fused coating is compressed in the same position as deposited by the distributing means, andv a power transmission for operating said rollers to advance the travelling web at a uniform speed through the machine.

7. In a machine of the character described, means for moving a base web through the machine at a uniform speed, a receptacle for coating material including a distributing means mounted to feed coating material from the receptacle onto said moving web, said distributing means including a rotary roller having flutes on the surface thereof in parallel alignment to the axis of rotation arranged to extend into the receptacle for taking a measured quantity of coating material therefrom, spaced rotary brushes contacting the roller to assure positive removal of said material from the roller fluted surfaces, and brush means coacting with one of said rotary brushes for keeping the latter free from said material.

8. In a machine for manufacturing heat sealing filter sheet material, means for continuously moving a base layer web formed of a porous fiber structure through the machine at a uniform speed, means for depositing measured quantities of a dry fluent coating material in a thin layer on the moving web, means for partially fusing said coating in the thin layer as deposited on the moving web, and means for compressing the coating while in partially fused state to conform and adhere to the fiber structure of the web forproviding a pervious lamina of substantially the same porosity as the web, said means for compressing the coating includes a plurality of spaced rollers of progressively increasing diameter driven at uniform speed to keep the moving web taut and in tension.

HANS 0. IRMSCHIER. 

